MIC2937A-3.3BU Micrel Inc, MIC2937A-3.3BU Datasheet - Page 9

• Manufacturer Part Number: MIC2937A-3.3BU
• Description: IC REG LDO 750MA 3.3V TO263
• Manufacturer: Micrel Inc

Specifications of MIC2937A-3.3BU

• Regulator Topology: Positive Fixed
• Voltage - Output: 3.3V
• Voltage - Input: Up to 26V
• Voltage - Dropout (typical): 0.37V @ 750mA
• Number Of Regulators: 1
• Current - Output: 750mA
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: TO-263-3, D²Pak (3 leads + Tab), TO-263AA
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Current - Limit (min): -

MIC2937A/29371/29372
with a bypass capacitor across R
frequency gain from 4 to unity. Pick
or about 0.01µF. When doing this, the output capacitor must
be increased to 10µF to maintain stability. These changes
reduce the output noise from 430µV to 100µV
kHz bandwidth at 5V output. With the bypass capacitor added,
noise no longer scales with output voltage so that improve-
ments are more dramatic at higher output voltages.
Typical Applications
*MINIMUM INPUT-OUTPUT VOLTAGE RANGES FROM 40
Figure 4. MIC29372 Wide Input Voltage Range Current Limiter
May 2006
DEPENDING ON LOAD CURRENT.
Figure 2. MIC2937A-5.0 Fixed +5V Regulator
GND
+V IN
+V IN
GND
C
V
V IN
IN
BYPASS
ADJUST
V
OUT
V
OUT
≅
2 R
π
+
1
V OUT ≈ V IN
, since it reduces the high
1
10µF
• 200 Hz
1
V OUT = 5V
m
V TO 400
RMS
m
for a 100
V,
9
Automotive Applications
The MIC2937A is ideally suited for automotive applications
for a variety of reasons. It will operate over a wide range of
input voltages with very low dropout voltages (40mV at light
loads), and very low quiescent currents (100µA typical). These
features are necessary for use in battery powered systems,
such as automobiles. It is a “bulletproof” device with the abil-
ity to survive both reverse battery (negative transients up to
20V below ground), and load dump (positive transients up to
60V) conditions. A wide operating temperature range with low
temperature coefficients is yet another reason to use these
versatile regulators in automotive designs.
ON
SHUTDOWN PIN LOW= ENABLE OUTPUT. Q1 ON = 3.3V, Q1 OFF = 5.0V.
Figure 5. MIC29372 5.0V or 3.3V Selectable Regulator with
Shutdown.
SHUTDOWN
INPUT
3.3V
ON
V OUT = V REF x (1 +
SHUTDOWN
INPUT
Input
0
1
OFF
Output
5V
Figure 3. MIC29372 Adjustable Regulator
3.3V
5.0V
SHUTDOWN
GND
OFF
+5V to +7V
+V IN
SHUTDOWN
470 k Ω
ADJUST
GND ADJUST
V
R
R
OUT
1
2
V
)
IN
V
REF
100pF
V
220k Ω
1%
MIC2937A/29371/29372
OUT
2N2222
1.23V
300k Ω
180k Ω
1%
1%
R .01
R
V
1
OUT
1.2V
2
µF
+
Micrel, Inc.
V CC OUT
10µF
10µF
26V